Methods and devices for printing seals for fuel cell stacks
View Patent ↗Various embodiments include a fuel cell stack seal application method including the step of applying a seal paste to a fuel cell, placing the fuel cell in a fuel cell stack, and thermally treating the fuel cell stack to set the seal paste into a seal. Further embodiments include applying the seal paste to an interconnect using stencil printing.
1. A method of forming a seal on a fuel cell, comprising:
placing a first stencil having a first open space and first solid webbings on the fuel cell, the first open space defining a shape of the seal;
applying a first seal paste to the first stencil to fill the first open space, the first solid webbings occupying first locations in the first open space filled with the first seal paste;
removing the first stencil from the fuel cell to expose the first locations that were occupied by the first solid webbings, gaps appearing at the first locations in the first seal paste;
placing a second stencil having a second open space and second solid webbings on the fuel cell, the second stencil being placed such that the first seal paste is within the second open space and the second solid webbings occupy second locations different from the first locations where gaps appear in the first seal paste;
applying a second seal paste to the second stencil to fill the second space, including the gaps;
removing the second stencil;
placing the fuel cell in a fuel cell stack; and
thermally treating the fuel cell stack to set the first and second seal pastes into the seal.
2. The method of claim 1 , wherein the first stencil comprises a solid outer portion and a solid inner portion connected by the first solid webbings, the solid outer portion and the solid inner portion defining the first open space.
3. The method of claim 1 , wherein the second stencil comprises a solid outer portion and a solid inner portion connected by the second solid webbings, the solid outer portion and the solid inner portion defining the second open space.
4. The method of claim 1 , wherein the fuel cell stack is a solid oxide fuel cell stack containing solid oxide fuel cells.
5. The method of claim 1 , wherein the first open space, the shape of the seal, and the second open space are of a hollow rectangle shape, a ring shape, or a strip shape.
6. A method of forming a seal on an interconnect, comprising:
placing a first stencil having a first open space and first solid webbings on the interconnect, the first open space defining a shape of the seal;
applying a first seal paste to the first stencil to fill the first open space, the first solid webbings occupying first locations in the first open space filled with the first seal paste;
removing the first stencil from the interconnect to expose the first locations that were occupied by the first solid webbings, gaps appearing at the first locations in the first seal paste;
placing a second stencil having a second open space and second solid webbings on the interconnect, the second stencil being placed such that the first seal paste is within the second open space and the second solid webbings occupy second locations different from the first locations where gaps appear in the first seal paste;
applying a second seal paste to the second stencil to fill the second space, including the gaps;
removing the second stencil;
placing the interconnect in a fuel cell stack; and
thermally treating the fuel cell stack to set the first and second seal pastes into the seal.
7. The method of claim 6 , wherein the first stencil comprises a solid outer portion and a solid inner portion connected by the first solid webbings, the solid outer portion and the solid inner portion defining the first open space.
8. The method of claim 6 , wherein the fuel cell stack is a solid oxide fuel cell stack containing solid oxide fuel cells.
9. The method of claim 6 , wherein the first open space, the shape of the seal, and the second open space are of a hollow rectangle shape, a ring shape, or a strip shape.
10. The method of claim 6 , wherein the second stencil comprises a solid outer portion and a solid inner portion connected by the second solid webbings, the solid outer portion and the solid inner portion defining the second open space.
11. A method of forming a seal on a fuel cell component, comprising:
placing a stencil having an open space and solid webbings on the fuel cell component, the open space defining a shape of the seal;
applying a first seal paste to the stencil to fill the open space, the solid webbings occupying first locations in the open space filled with the first seal paste;
re-arranging the stencil to move the solid webbings to second locations different from the first locations, gaps appearing at the first locations in the first seal paste;
applying a second seal paste to the stencil to fill the open space, including the gaps;
removing the stencil;
placing the fuel cell component in a fuel cell stack; and
thermally treating the fuel cell stack to set the first and second seal pastes into the seal.
12. The method of claim 11 , wherein re-arranging the stencil comprises rotating the stencil.
13. The method of claim 11 , wherein the seal is symmetric about an axis.
14. The method of claim 13 , wherein re-arranging the stencil comprises flipping the stencil 180 degrees about the axis of the seal.
15. The method of claim 13 , wherein the solid webbings on the stencil are not symmetric about the axis of the seal.
16. The method of claim 11 , wherein the fuel cell component is a fuel cell.
17. The method of claim 11 , wherein the fuel cell component is an interconnect.